Yes, it does help, pcwriter, thanks. I already have S2Member installed and activated – I use it for overall privilege control, but it still uses only the WordPress basic priv levels – subscriber, contributor, author (which in my WP, does nothing), editor and admin. What I need is more granularity – to be able, for example, to allow a single subscriber or contributor member to access two specific pages for write, and read the rest. Role Scoper says it does this, but Role Scoper crashes my website. Can you tell me how to use S2Member (a very fine plugin!) to add more privs by page capability to my website?

The easiest way to set this up with s2member would be to go to the user’s profile in your WP backend and assign that member the “Role” of “s2member Level 4″. Then go to edit the page you want to restrict access to and, in the “s2member” section at top-right, select “Require Level #4″ at “Page Level Restriction?”. I haven’t tried this myself, but it should work to restrict access to that page to only those members who have a Level 4 membership (whether paid or not, doesn’t matter).

For even more granular control, see the following 2 sections under “s2member” > “API/Scripting”:
“Using Advanced Conditionals” & “Custom Capabilities”.

Actually, I want to do the reverse of what you outlined – I want to allow a S2Member #1 (contributor) member to have the expected read-only access to the entire website, EXCEPT I want that same member to also have edit capability on two pages of the website only. In other words, I don’t wish to restrict this member from any pages, but instead I wish to grant that member edit access to two pages he would ordinarily would only be able to read, as well as read access to the rest of the website.